Hillbilly Heater

Industry Standards

• Hillbilly heater - 20 sf or 2 sq meters per 500' roll of tubing - $75 - [1]
• Amazon - 4 sf - $124 - [2]
• Evacuated tube - 5 sf - $179 + $230 ship - [3]
• Evacuated - $670 - 15 sf - [4]

System Goals

Exchange Solar heat to aquarium water.

Efficiency

Heat transfer is limited by the thermal conductivity of the pipe (PEH ~0.5 W/m K good for plastics). Is high-pressure system ideal or is a low-pressure gravity system possible using black gutter(s) etc.? Can water be mixed directly or is thermal mixing a bigger problem? Can temperature be managed by pump control?